Question

the main component of egg shells is the compound calcium carbonate, caco₃. if you react egg shells with acetic acid, hch₃coo, from vinegar, the following reaction will take place. caco₃(s) + 2hch₃coo(aq) → h₂o(l) + co₂(g) + ca(ch₃coo)₂(aq) if 4.421 grams of carbon dioxide, co₂, was produced from 10.57 grams of egg shells, what percentage of the mass of the egg shells was calcium carbonate?

Explanation:

Step1: Determine molar - mass of CO₂

The molar - mass of CO₂ is $M_{CO_2}=12 + 2\times16=44$ g/mol.

Step2: Use stoichiometry

From the reaction, 1 mole of CaCO₃ produces 1 mole of CO₂.

Step3: Calculate mass of CaCO₃

Mass of CaCO₃ that produced 4.421 g of CO₂: $m_{CaCO_3}=\frac{4.421}{44}\times100 = 10.05$ g.

Step4: Calculate percentage

Percentage of CaCO₃ in egg - shells: $\frac{10.05}{10.57}\times100\approx95.1\%$

Answer:

95.1%